The present disclosure relates to a catheter assembly which is to pierce and to remain in a blood vessel of a patient at a time of transfusion, for example.
Conventionally, at the time of performing transfusion in a patient, a catheter assembly is used, for example. This type of catheter assembly includes a hollow catheter, a catheter hub secured to a proximal end of the catheter, a hollow inner needle inserted inside the catheter and having a sharp needle tip at a distal end, and a needle hub secured to a proximal end of the inner needle. To reduce the puncture resistance, the diameter of the catheter distal end is reduced, and a catheter inner surface and an inner needle outer surface are in close contact with each other at the reduced diameter part. When this close contact continues for a long time, the catheter inner surface and the inner needle outer surface become adhered to each other, and it becomes difficult to perform operation of moving the catheter forward with respect to the inner needle in order to insert the catheter into a blood vessel. Accordingly, with a conventional catheter assembly having a structure where a catheter hub is connected to a distal end of a needle hub, in many cases, adhesion is released by relatively rotating the catheter hub and the needle hub before piercing.